1. Field of the Invention
The present invention relates to an acoustic projector and more particularly to a tuned plate acoustic projector that has a hemispherical beam pattern.
2. Description of the Prior Art
There has been a continuing requirement for acoustic projectors that can be mounted flush to the surface of a moving object, such as underwater ordinance, and transmit broad hemispherical beam position locating signals. In the past broad hemispherical beams have been obtained by employing array type acoustic projectors comprising a plurality of acoustic projectors. These array type projectors have been relatively complex and unreliable. Individual acoustic projectors have also been used; however, these have been quite directional and have not been able to generate broad hemispherical acoustic beams that are 90.degree. off the axis of the acoustic projection. off
The present invention overcomes these difficulties by providing a flush mounted acoustic projector that is reliable, relatively simple and generates a broad hemispherical beam that is 90.degree. off its axis to materially aid in locating and tracking the object upon which it is mounted.